There are many types of surgical procedures where the surgeon must perform various operations on moving organs or tissue within the human body. For example, there has recently been an effort to perform coronary artery bypass surgery on a beating heart, without using cardiopulmonary bypass and a heart-lung machine. During a typical coronary bypass procedure, a bypass graft is used to help reestablish coronary artery circulation when a portion of the coronary artery is stenosed. Typically the graft vessel used in bypassing the stenosed portion of the coronary artery comprises one or more segments of the patient's saphenous vein or internal mammary artery.
Once the graft vessel is harvested and prepared, one end is sutured to the aorta, near its base, and the other end is attached to the coronary artery, just distal to the blockage. Some surgeons choose to complete all the proximal anastomosis, to the aorta, before commencing the distal anastomosis to the coronary arteries. In contrast, others choose to complete the distal anastomosis first. Regardless of the order, when undertaking the distal anastomosis to the coronary artery, it is important that the vessel graft be held steady and adjacent the coronary artery, with a minimum of vascular trauma and a minimum of visual and surgical obstruction by instruments in the narrow operative field.
The speed of performing such anastomosis can become extremely critical as well, especially during procedures where the heart is kept beating. Often the coronary artery is occluded during the procedure to reduce blood loss through the arteriotomy. It is very important to reconnect the supply of blood to the artery as soon as possible in order to minimize or prevent damage to the patient such as damage to the myocardium. Blood vessels are now normally anastomosed end-to-end or end-to-side by suturing techniques. Conventionally, to suture two vessels together, a surgeon passes the pointed tip of a curved suturing needle, having a suture attached to the blunt end, through the coronary artery, into the lumen of the vessel and back out through the graft vessel. Then, the surgeon grasps the tip of the needle which has been forced through the tissues with fingers or a needle holder and pulls the needle through the tissues, wherein the suture follows the curved path of the needle. Usually a knot or button is present at the trailing end of the suture to anchor the first stitch. After the surgeon has pulled the suture entirely through the tissues to tension the first stitch, he or she then forces the tip of the needle through the coronary artery again, at a location spaced from the first stitch, until the needle again goes through the coronary artery, into the lumen of the vessel and back out through the graft vessel. Again, he grasps the tip of the needle which has been forced through the tissues, applies tension to the needle pulls the entire suture through the tissues to complete the second stitch. This process is repeated again and again, with the surgeon tensioning the suture after each stitch to draw the tissues together thereby creating a running or continuous stitch, composed of individual thread loops, which extends around the graft vessel.
Needless to say, performing vessel anastomosis, such as described above, can become very difficult, especially when performed on a beating heart. Suture anastomosis procedures on non-beating hearts generally take the skilled surgeon anywhere from ten to twenty minutes to complete for each anastomosis. Therefore, there has been some attempts to provide a device for stabilizing or immobilizing a portion of the heart, preferably a portion near the anastomosis site, so that the surgeon can more readily complete the bypass procedure. In the past the surgeon would use a pair or forceps or a metal fork-type device to push against a portion of the heart, near the anastomosis site to keep the heart relatively still so that bypass procedure could be performed.
Another type of stabilization device is called a "vacuum based" device. The benefit of vacuum based devices is that they have members which grab onto a portion of the heart by suction and lift it up in order to immobilize it. This is often a better method of stabilizing the beating heart. An example of such a device is given in PCT International Publication Number WO 97/10753, published on Mar. 27, 1997 and which is hereby incorporated herein by reference. However, this device has many disadvantages, including a low integrity vacuum seal between the device and the heart caused by any number of reasons including particulate being trapped in the vacuum tube.